Toilet filling

[Money2Burn]

2012 Coachman Brookstone fifth wheel. While filling the water tank the toilet valve allows water to fill the bowl and would eventually overflow if we didn’t sit there and keep hitting the flusher. When I put the system back in normal use mode after filling then everything is ok. Any ideas?

[Falconman]

What’s the water pressure of the line you’re filling it with? Sounds like it might be high enough to overcome the toilet valve.